Dyeing process



Patented Aug. 11, 1942 DYEING PROCESS Cyril -M. Croft, Cumberland, Md, asslgnorto Celanese Corporation of America, acoriorl tlon of Delaware No Drawing. Application May 2, .1940,

Serial No. 332,9

Claims. (cu-24),

This invention relates to the coloring of textile materials and relates more particularly to a process of coloring yams, filaments or fabrics comprising organic derivatives 'of cellulose.

An object of this invention is to dye textile materials comprising organic derivatives of cellulosic in a rapid and economic manner.

' Another object of this invention is to dye said textile materials comprising organic derivatives of cellulose with dyestufl's which when applied in the ordinary manner have little or no aflinity for organic derivatives of cellulose.

Still another object of this invention. is to dye mixed textile materials containing other materials besides organic derivatives of cellulose with dyestuffs which ordinarily have no affinity for organic derivatives of cellulose so that a dyeing of the organic derivative of cellulose may be obtained without afiecting-the other materials or, if desired, the entire mixedmaterial may be dyed uniformly.

Other objects of this invention will appear hereinafter from the following detailed description and claims.

In the dyeing of textile materials it is frequently desired to dye materials which are. composed of more than one type of flbe Such textile material may be composed of yarns of organic derivatives of cellulose mixed with yarns of other fibers such as cotton, reconstituted cellulose, natural silk and wool. In some cases it is desired to dye these mixed materials a single color, while in other cases it is desired to obtain differential, color eflects by dyeing one type of fiber in the mixed material one color and leaving the remaining fiber or fibers uncolored. In some instances, this may be done by choosing dyes which have an amnity for one of the materials and little or no afllnity for the others. This procedure is limited, however, by the. fact that of the dyestufls which are commercially available, relatively few which are otherwise ac-- ceptable from the standpoint of fastness to light, washing, rubbing, scouring, etc., exhibit any sharp distinctions in the type of fibers they will dye and in the types they will leave untouched. As a result the number of colors available for use in obtaining. such differential color effects is definitely limited. It is, therefore, obvious that any process which will make available classes of dyestuffs for the differential dyeing of organic derivatives of cellulose mixed with other I fibers is an important advance in the art.

I have .now discovered that acid dyestuffs which which ordinarily show practically no 'afilnity for organic derivatives of cellulose, may now be used for dyeing cellulose derivative materials and particularly for the differential dyeing of mixed ma terialscontaining organic derivatives of cellulose to color the organic derivative of cellulose and yet leave the other'materials.uncolored and unstained; According to my process, a materia such as a yarn madefrom wool mixed with staple fibers of an organic derivative of cellulose is treated withan' aqueous dye bath containing an acid; wool dyestufi and a water miscible organic solvent having little or no solvent action on the organic derivative of cellulose. By this procedure one would ordinarily expect the wool contained insaid mixed material to be dyed by said acid wool dyestufl and the cellulose acetate to remain uncolored. However, this proces of dyeing was found to leave the wool undyed and unstained by the acid wool dyestufl while the organic'derivative of cellulose, for which said dyestufi's normally show substantially no aflinity,

were dyed'desirable deep shadeswhlch'are very.

fast to light, scouring, washing and rubbing.

While my process is eminently suitable for the diflerentlal dyeing of organic derivatives of cellulose when mixed with other textile materials by suitable variations in the composition of the dye bath it is possible not only to dye the organic derivative of cellulose material but also to dye the materials which are mixedwi'th it as well. and thereby obtain a mixed material uniformly dyed in a solid shade. This, may be accomplished by adding a water miscible lower aliphatic acid to the dye bath containing the acid wool dyestufl! and the organic solvent. By the addi tion of such an acid to the dye bath both the organic derivative of cellulose material and the animal fiber material mixed therewlth, such as W001 or silk, are dyed at the same time. In this manner a uniformly dyed mixed wool-cellulose derivative orsilk-cellulose derivative textile material may be obtained, as a result which has been heretofore obtainable with dimculty and only after an elaborate and complicated procedure.

The organic solvents for the dyes suitable for use in accord with my invention are-preferably water-soluble and should have" substantially no solvent power for the organic derivatives of cellulose which are being'dye'd. They should, however,havea.slight swelling action on said organic derivatives of cellulose which enablesthe dyestuil! to penetrate more rapidly. Organic sol- I vents which may be mentioned as particularly are generally used for'the dyeing of wool, and desirable. are the aliphatic alcohols such as form of packages.

. examples are given:

f methylffethyl, propyl and isopropyl alcohol. The

tain acids thereto. The acids which may be added should be miscible with water and are organic solved in a 50:50 mixtureby volume of ethyl alcohol and water. The hanks are 'moved about-in the dye bath maintained at room temperature for about 30 minutes. After removal from the bath the excess liquid in the hanks is then drained oil and the hanks centrifuged and dried. The hanks are then washed in a V; grain per liter soap solution at 50 C. and finally scoured in a soap solution at 50" C. Upon examination it is noted that the cellulose aeetate'is 'dyed a full blue shade in character, preferably of the lower-aliphatic series. Acids such as acetic, acid and formic acid are particularly suitable for use in my'process. the dye bath may vary from 1.0% to about 15.0%,

depending upon the particular dyestufl used and The concentration of acid maintained'in the character of the mixed material being1dyed.-'20

By suitably varying the acid concentration of the depth of-shade to which each-fiber is dyed. In

L this r'nanner a pleasingt'wo-toneeil'ect'of light and dark shades may be obtained.

- The presence of water in the dye bath is ad? vantageous and water may comprise up to about f 50.0% by volume but'from about 45.0% to about 50.0% is preferable. Very desirable results'are I I obtained when ethyl alcohol mixed in equal parts by-volume with water is used asthe solvent.

The dyestuffs suitable 'in'my process are-those acid dyes generally used for thedyeing ofwool and which have no substantive afllnity for organic derivatives of cellulose. Examples of such acid dyes which may be used are W001 Blue GL (Color Index No. 833) Alizarine Light Green 266- (Color Index No. 1078), Alizarine Fast Violet R. (Color Index No. 1073), and'Aliz'arine Direct Blue A.

' The amount of the-dyestuti used in the dyebath will, of course, vary with the depth of the shade desired, but generally I' prefer to use about 1 part to about parts by weight of dyestuif to each thousand parts by volume of the dye bath.

The temperature at which the dye bath is maintained in dyeing these mixed materials will vary with thesolvent medium employed as well as with the dyestuif being'us'ed. In some instances the dye bath maybe maintained at about room temperature while in other instances the dye bath is preferably maintained at temperatures of'from-25" C. to about 60 C l?eriods of immersion varying from about 5 minutes to about hour are generally preferred. The'mat'erial'may be dyed in the form of hanks or skeins of yarn but preferably is dyed in the be used in my process may be cellulose esters or cellulose ethers. jSuch' esters may be'cellulose acetate, cellulose 'propionate and acetate-butyrate, while such suitableethers may be ethyl cellulose,fmetliy1 cellulose and benzyl cellulose.

In. order to further illustrate my invention, but without being limited Example I thereto, the following dye bath it is possible not only to dye all the fibers' in themixed material-but to control the while the wool is left perfectly white. The mixed yam may likewise be dyed in package form in this manner and the same desirable results obtained.

' Example 11 A" mixed wool and cellulose acetate yarn in package-form isimmersed in a dye bath containing 910' parts by volume of ethyl alcohol, 15 parts by volume of acetic acid, 45 parts by volume of water and 2 grams per liter of W001 Blue GL.

The dye bath is maintained at C. and the liquid is circulated through the packages for about 45 minutes. -.The.dye liquid retained in "the packages is drained, and a'soap' solution; at about 50 C. containing about /2 gram of .soap per liter is circulated through the packages. After .washing and scouring it is noted that both the cellulose acetate and'the wool are'dyed uniformly 30 to an even blue shade.

Example III p A yarnfcf mixed cellulose acetate and real silk in'pa'ckage formis immersed in a dye bath containing 40 parts by volume of ethyl alcohol, 15

parts by volume of formic acid, parts by volume of water and 2 grams per liter of Wool Blue GL. The dye bath is maintained atabout 30 C.

and is circulated through the'packages for about 40 one-half hour. The'excess dye liquidis'removed from the'packages and a dilute soap solutionis circulated through the packages at about C.

v The mixed yarn is dyed uniformly and both the '45 lose acetate yarns may also be Likewise, mixed materials in Hanksof a yarn composed of a mixtureof cellulose acetate staple fiber and wool are immer sed in 10 times their'weight of .adye bath cellulose acetate and silk are dyed to a leveland even full blue shade. Mixed real silk and celludyed in hank or skein form. f v a It is to be understood that the foregoing detailed description is merely given by way of illustration and that many variations may be 50 made therein without departing from the spirit 1. Method for the coloration of a mixedmateri'al containing'fibers of an organic derivative of cellulose-and animal ilbers,vwhich comprises-applying to said material a dyebath that has no solvent power for the organic derivative of cellulose buthas a slight swelling action onfthe 50 same and comprising a solution in an organic 3 miscible'orga'nic acid, a neutral water miscible organic liquid which is a solvent for the dye and an amount of wateryif any, not exceeding 50% by volume of the dye bath, whereby substantial dyeing of both the organic derivative of cellulose and animal nbers is effected.

2. Method for the coloration of a mixed material containing fibers of cellulose acetate and animal fibers, which. comprises applying to said material a dyebath that has no solvent power Y 1 containing 2 grams per liter of W001 Blue GL dis- 7 for the cellulose acetate but has a slight swelling.

action on the same and comprising a solution in an organic liquid medium of an acid dyestufi which has at most slight afiinity for the cellulose acetate when applied from an aqueous bath, said organic liquid medium comprising a water miscible organic acid, a neutral water miscible organic liquid which is a solvent for the dye and an amount of water, if any, not exceeding 50% by volume of the dye bath, whereby substantial dyeing of both the cellulose acetate and animal fibers is eflected.

3. Method for the coloration of a mixed material containing .fibers of cellulose acetate and wool fibers, which comprises applying to said material a dyebath that has no solvent power for the cellulose acetate but has a slight swelling action on the same and comprising a solution in an organic liquid medium of an acid dyestufi which has at most slight affinity for the cellulose acetate when applied from an aqueous bath, said organic liquid medium comprising a watermiscible organic acid, a neutral water miscible organic liquid which is a solvent for the dye and an amount of water, if any, not exceeding 50% by volume of the dye bath, whereby substantial dyeing of both the cellulose acetate and wool fibers is efiected.

4. Method for the coloration of a mixed material containing fibers of an organic derivative of cellulose and animal fibers, which comprises app y ng to said material a dyebath that has no solvent power for the organic derivative of cellulose but has a slight swelling action on the same and comprising a solution in an organic liquid medium of an acid dyestufi which has at most slight aifinity for the organic derivative of cellu-, lose when applied from an aqueous bath, said organic liquid medium comprising a watermiscible lower aliphatic acid, a neutral water miscible organic 'liquid which is a solvent for the dye and an amount of water, if any, not exceeding 50% by volume of the dye bath, whereby substantial dyeing of both the organic derivative of cellulose and animal fibers is effected.

5. Method for the coloration of a mixed material containing fibers oi. cellulose acetate and animal fibers, which comprises applying to said material a, dyebath that has no solvent power for the cellulose acetate but has a slight swelling action on the same and comprising a solution in an organic liquid medium of an acid dyestufi which has at most slight afiinity for the cellulose acetate when applied from an aqueous bath, said organic liquid medium comprising a water miscible lower aliphatic acid, a water miscible alcohol which is a solvent for the dye and an amount of water, if any, not exceeding 50% by'volume of the dye bath, whereby substantial dyeing of both the cellulose acetate and animal fibers is effected.

6. Method for the coloration of a mixed material containing fibers of cellulose Y acetate and wool fibers, which comprises applying tosaid material a dyebath that has no solvent power for the cellulose acetate but has a slight swelling action on the same and comprising a solution in an organic liquid medium of an acid dyestufl' which has at most'slight afilnity for the cellulose acetate when applied from an aqueous bath, said organic liquid medium comprising a water miscible lower aliphatic ac'id, ethyl alcohol and an amount of water, if any, not exceeding 50% by volume of the dye bath, whereby substantial dyeing of both the cellulose acet te and wool fibers is effected.

7. Method for the coloration oi a mixed material containing fibers of cellulose acetate and wool fibers, whichcomprises applying to said material a dyebath'thathas no solvent power for the cellulose acetate but has a slight swelling action on the same and comprising a solution in an organic liquid medium of an acid dyestufi' which has at most slight affinity for the cellulose acetate when applied from an aqueous bath, said organic liquid medium comprising a water miscible lower aliphatic acid, methyl alcohol and an amount of water, if any, not exceeding 50% by volume of the dye bath, whereby substantial dyeing of both the cellulose acetate and wool fibers is effected.

8. Method for the coloration of a mixed material containing fibers of cellulose acetate and wool fibers, which comprises applying to said material a dyebath that has no solvent power for the cellulose acetate but has a slight swelling action on the same and comprising a solution in an organic liquid medium of an acid dyestufi which has at most slight afiinity for the cellulose acetate when applied from an aqueous bath, said organic liquid medium comprising a water miscible lower aliphatic acid, propyl alcohol and an amount of water, if any, not exceeding 50% by volume of the dye bath, whereby substantial dyeing of both the cellulose acetate and wool fibers is effected.

9. Method for the coloration of a mixed material containing fibers of cellulose acetate and wool fibers, which comprises applying to said material a dyebathsthat has no solvent power for the cellulose acetate but has a slight swelling action on the same and comprising a solution in an organic liquid medium of an acid dyestufi which has at most slight afiinity for the cellulose acetate when applied from an liquid medium comprising acetic acid, ethyl alcohol and an amount of water, if any, not exceeding 50% by volume oi the dye bath, whereby substantial dyeing of wool fibers is eifected.

10. Method forthe coloration of a mixed material containing fibers of cellulose acetate and animal fibers, which comprises applying to said material a dyebath that has no solvent power for the cellulose acetate but, has a slight swelling action on the sameand comprising a solution in an organic liquid medium of an acid dyestufi which has at most slight aflinity for the cellulose acetate when applied from an aqueous bath, said organic liquid medium comprising formic acid,'ethyl alcohol and an amount of water, if any, not exceeding 50% by volume of the dy bath, whereby substantial dyeing of both the cellulose acetate and animal fibers is efiected.

c an. M. cRoFr.

aqueous bath, said organic both the cellulose acetate and 

